Hi. First of all. I want to say what a great thing it is that you have rescued a dog from the shelter - especially one as old as she is and one with a history such as hers. Others would have just walked away.
Now for the timidness. This is most probably a result of how she was treated prior to getting to a shelter and prior to getting to you. The cut vocal cords alone show how much abuse the dog has been through. Dogs like that either tend to be very aggressive or they could be a timid as your dog is. What you have to is to make your dog feel more comfortable around you, your wife, and other people - but then again, you already know that. You then have to understand that this takes a lot of time and it can take a lot of effort too.
Show the dog that she is loved and she will gradually warm up to you. She may not like to be petted now - she may fear human contact because of what happened to her in the past, but with constancy, she will learn to love it. Her following you around is already a sign that she trusts you. Just take your time with her, she'll come around. She even has the potential to be a very loving and protective companion.
